Expression of stem cell marker in side population cells isolated from human gallbladder carcinoma cell line GBC-SD

Abstract

Objective:To investigate the existence of side population cells with the potency of stem cells in human gallbladder carcinoma cell line GBC-SD and the differences in ABCG2,Oct-4 and CD34 expression among SP cells,non-SP cells and GBC-SD cells.Methods:SP and non-SP cells were sorted from GBC-SD cells by fluorescence-activated cell sorting (FACS).The expression of ABCG2,Oct-4 and CD34 in SP cells, non-SP cells,and GBC-SD cells was detected by reverse transcription-polymerase chain reaction (RT-PCR), Western blot,flow cytometry (FCM) and immunofluorescence chemistry.Results:SP cells with stem cell potency were isolated from GBC-SD cells with a proportion of (0.64±0.08)%.The metastatic ability of SP cells was obviously higher than that of non-SP cells and GBC-SD cells (P0.05).The expression of ABCG2 was significantly higher in SP cells than in non-SP cells and GBC-SD cells [(89.56±3.86)% vs.(1.32±0.49)% and (12.37± 1.61)%,P=0.0011.The expression of Oct-4 in these cells was (94.87±1.40)%,(88.16±2.34)% and (90.17± 1.61)%,respectively (P0.05).CD34 was nearly absent in these cells on protein level [(1.78±0.51)% vs. (0.63±0.21)% and (0.96+0.381)%,P0.05)],but it was highly expressed in non-SP cells and GBC-SD cells and absent in SP cells on mRNA level.Conclusion:SP cells,which have the potency of stem cells,exist in hu- man gallbladder carcinoma GBC-SD cell line and have the phenotype of ABCG2+Oct-4+CD34-.